Hi @pabou, that’s an interesting use case I have not yet heard of. Except for the inverted logic, there is (to my understanding) one other issue to solve: The Shelly needs to measure the actual consumption on the radiator so that Opportunity Loads can make the right decision.
One solution would be to use a Shelly EM Gen3, which has separate relay and power measurement, and tie reverted relay logic and measured consumption together using a small Node-RED flow. We are planning to publish some examples on how to use Opportunity Loads together with Node-RED.
Look good. I’ll procure a 1pmgen4 to test as soon as 3.8 is out. One question, why do you need to have pm capabilities ? Those load are fixed and could be configured statically ? Unless you think it is too user unfriendly to have to figure out the watt rating of an installed heater (fair, the label is usually not easy to read)
You’re not the first person that wonders about that requirement. The reason in your case is, that in the moment the radiator reaches its configured temperature and it shuts off, Opportunity Loads needs to know about it. Without knowing the actual power, Opportunity Loads would have to “reserve” the configured power for this device, which would prevent potentially other available devices from running. With Node-RED, you can of course send a fake fixed power measurement to Opportunity Loads, if blocking other devices from using surplus is not a concern in your case.
(I live in the french alps and in winter electric heater rarely disconnect from the local thermostat )
I know you can drive the victron ev charger as a variable load. Are you aware of any other “variable load” which would fit in the victron ecosystem, and which I could use to drive an electric heater (water or else).
I am currently using such a device (eddi from a uk company myenergi), which can heat a resistance which whatever surplus is available.
The idea is to never export, whatever the combined/combinatorial power rating of all other heaters being driven with simple on/off
It works, but I am facing the usual headache of having 2 ecosystems competing for the surplus
For info i have: multiplus2, mptt 150/70, smart shunt, battery sense, battery protect, cerbo, link distributor, em112
Are the Inverter RS Smart and Inverter RS Smart Solar supported inverters for this new Opportunity Loads feature? The draft manual does not list the Inverter RS models only the Multi RS models?
Hi @forest-gecko, it is as written in the manual: inverters (Inverter RS as well as inverters with VE.Bus or VE.Direct) are currently not supported. But we consider adding support for them in a future release.
Thanks for your reply @ptrenz , okay, good to know. I understand now that only inverter/chargers are currently supported as this is likely easier to support handling loads turning off suddenly etc.
I am glad that inverter only models are being considered for addition in a future release as it would be very handy to be able to use the Opportunity Loads feature in all systems that I design!
The draft manual linked in the first post in the thread (http://ve4.nl/ol-manual) does not seem to mention what you quoted, at least as far as I could tell, is there another more up to date manual somewhere?
So I run a Midnite Rosie inverter/charger as a dc load on my cerbo, off grid.
Would it be possible to support the VM-3P75CT energy meter as the “inverter charger” to allow for non quattro/multiplus inverter support?
I guess I dont understand why even my ve direct 48/1200 inverter wouldn’t work. Because in an off grid system most would not be running the charger of the inverter, I run double conversion using ip43 48/13 etc to charge battery bus directly if I do need to supplement pv production.
Use case would be things like turn on shelly gen 4 us plug (connected to dehumidifier) if solarsense 750 has 1kW of excess production versus actual pv production and soc over 75% etc.
we don’t have plans to add support for non-Victron inverters or inverter/chargers. The power-steering algorithm of Opportunity Loads needs to know the exact capabilities of the inverter: per-phase power capacity, safe continuous ratings, operating mode, etc. Without this data, Opportunity Loads cannot operate reliably under all conditions. This is also why we started with inverter/chargers only.
Use case would be things like turn on shelly gen 4 us plug (connected to dehumidifier) if solarsense 750 has 1kW of excess production versus actual pv production and soc over 75% etc.
Yes, that’s an ideal use case for Opportunity Loads. Stay tuned for the planned support for the SolarSense 750 and Victron inverters.
We were wondering if the idea of the my-pv water heaters was received, and what you think about it. Not sure if it was overlooked, as the other proposals all triggered a reaction or discussion, but that one didn’t.
We really don’t want to appear annoying, just would like to know if it’s interesting or relevant.
Hi @icgt, yes, definitely received and noted. Heating rods which can be modulated are a perfect candidate for Opportunity Loads and the My-PV device with its open communication options is well suited for that. We’re currently looking into it and discussing possible solutions for it.
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